Microdialysis Studies

微透析探针技术为扩散组织成分的取样或生物活性物质的递送提供了进入组织间质的途径。然而，探针灌注液浓度与其组织对应物的关系是溶质分子量、溶质理化性质、组织性质、探针膜性质、探针几何形状、灌注速率和探针插入组织的创伤的复杂函数。正在研究这些依赖关系，以便改进该技术在数量上的有用性。大脑的应用正在与帕金森氏症、艾滋病、酗酒和滥用药物的研究有关。其他应用包括各种正常组织和肿瘤。内源性溶质包括多巴胺和喹啉酸。使用外源性物质的例子有齐多夫定（AZT）、乙醇和可卡因。数学模型用于描述探针内和周围组织中的扩散和对流溶质传输。需要了解探针的物理性质，如探针膜的扩散和对流渗透性，可以在体外的良好表征条件下确定。在动物（大鼠和灵长类动物）中进行的验证实验包括定量放射自显影、组织学和探针周围组织的化学分析，以及探针灌注浓度的测量。

Microdialysis probe technology provides access to tissue interstitium for either sampling of diffusible tissue constituents or delivery of bioactive substances. However, the relationship of the probe perfusate concentrations to their tissue counterparts is a complex function of solute molecular weight, solute physicochemical properties, tissue properties, probe membrane properties, probe geometry, perfusion rate, and the trauma of probe insertion into the tissue. These dependencies are being studied in order to improve the quantitative usefulness of the technology. Applications in the brain are being pursued in connection with Parkinson's disease, AIDS, alcoholism, and studies of drugs of abuse. Other applications involve various normal tissues and tumors. Endogenous solutes of interest include dopamine and quinolinic acid. Examples of exogenous substances employed are Zidovudine (AZT), ethanol and cocaine. Mathematical modeling is used to describe diffusive and convective solute transport within the probe and in surrounding tissue. Required knowledge of physical properties of the probes, such as diffusive and convective permeabilities of probe membranes, can be determined under well-characterized conditions in vitro. Validation experiments in animals (rats and primates) involve quantitative autoradiography, histology, and chemical assay of tissue surrounding the probe, as well as measurement of probe perfusate concentrations.